For many types of pain, the method for treating the pain is through administration of aspirin or any of a number of non-steroidal antiinflammatory agents, NSAIDs. Frequently, the administration of the NSAID provides the relief sought. However, if the relief of pain is insufficient with NSAIDs alone, these agents may be combined with orally effective morphine-like agents, such as codeine and other opioids. Because these two agents exert their effects by different mechanisms, combinations of these two classes of drugs usually can achieve an analgesic effect that would otherwise require a higher dose of opioid, but with fewer side effects. Nonetheless, even at a lesser dose of opioid, resulting in fewer side effects, it has been well documented that any dose of an opioid has the potential for severe side effects. For example, morphine and its related opioids may cause respiratory depression, nausea, vomiting, dizziness, mental clouding, dysphoria, pruritus, constipation, increased pressure in the biliary tract, urinary retention, hypotension, tolerance, and physical dependence. (The Pharmacological Basis of Therapeutics, 9th edition, Macmillan Publishing Co., 1996, pp 533-540.)
New safer and effective methods for the treatment of pain are in constant demand. The discovery of other agents which provide an analgesic synergism in combination with NSAIDs but have a reduction in the severity of the side effects profile are in constant demand. Such a combination is the subject of the present invention.
The present invention addresses a long felt need for a safe and effective treatment for pain.